This invention relates to gas turbine engines and, more specifically to methods for remanufacturing turbine vane clusters from salvageable vane components.
In a gas turbine engine of the type to which the present invention is directly applicable, working medium gases are burned in a combustion section and are expanded through a turbine section. Disposed within the turbine section are one or more rows of stator vanes which are adapted to direct the working medium gases to a preferred angle of approach into a downstream row of rotor blades.
The vanes of the turbine have a limited life and are among the most susceptible of gas turbine engine components to damage. The medium gases directed across the vanes are extremely hot and likely contain corrosive constituents. For example, the initial row of stator vanes in a modern turbine is exposed to gases having temperatures well in excess of two thousand degrees Fahrenheit (2000.degree. F.). Corrosive constituents contained within the medium gases include unreacted oxygen and oxides of sulfur. Violent energy reactions upstream of the stator vanes make it nearly impossible to control the homogeneity of the medium gases approaching the vanes. Accordingly, the vanes do not wear evenly and individual vanes are likely to need replacement before the entire set.
For ease of installation of the vanes and for aerodynamic performance considerations, it is conventional practice to form a row of stator vanes from clusters comprising a plurality of individual vanes each. The clusters are disposed in end to end relationship circumferentially around the working medium flow path. Paired vanes such as those illustrated in the present drawing are commonly employed although each cluster may also comprise three or more vanes.
To reduce replacement costs of vanes, designers and manufacturers of gas turbine engines have sought techniques for salvaging reusable portions of vane clusters and combination of salvaged portions to form remanufactured components.